v3.26.1
Cover - shares
 3 Months Ended
Mar. 31, 2026
Apr. 30, 2026
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2026  
Document Transition Report false  
Entity File Number 001-42504  
Registrant Name SIONNA THERAPEUTICS, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 84-2801521  
Entity Address, Address Line One 21 Hickory Drive, Suite 500,  
Entity Address, City or Town Waltham,  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 02451  
City Area Code 617  
Local Phone Number 819-2020  
Title of 12(b) Security Common Stock, $0.001 par value per share  
Trading Symbol SION  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   45,150,330
Central Index Key 0002036042  
Amendment Flag false  
Document Fiscal Period Focus Q1  
Document Fiscal Year Focus 2026  
Current Fiscal Year End Date --12-31